Azo dyestuffs



Patented Nov. 9, 1937 .Heinrich' Hopfi' and August Weickmann, Ludwigshafen-on-the-Rhine, Germany assignors to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. Application December 18, 1935, Se

rial No. 55,042.

4 Claims.

The present invention relates to the manufacture and production of azo dyestuffs.

We have found that azo dyestufis which are eminently suitable for dyeing cellulose esters and ethers can be obtained by coupling condensation products prepared by condensing aromatic. or heterocyclic compounds containing at least one reactive hydrogen atom, which compounds are free from sulphonic acid groups, with butylenel,2,3',4-dioxides with diazotized aromatic amines which are free from sulphonic acid groups or by diazotizing; ondensatiqn products of the said kind;which containefreeamino groups and coupling the diazocompounds thus obtained with coupling components, which are free from sulphonic acid groups.

Condensation products of the first kind may be coupled with diazo compounds in substance or on the fibre.

For example the azo dyestufi prepared by coupling with diazotized paranitriline, 1,4- dianilidobutane-2,3-diol (obtainable by condensing 1 molecular proportion of butylene-1,2,3,4- dioxide with 2 molecular proportions of aniline under a strong evolution of heat) dyes acetate artificial silk a reddish yellow shade.

If 1,4-dimeta-toluido-butane-2,3-diol (obtained by condensing 1 molecular proportion of butylene- 1,2,3A-dioxide with 2 molecular proportions of meta-toluidine under a strong evolution of heat) is coupled with diazotized para-nitraniline, an azo dyestuff is obtained which yields beautiful golden yellow dyeings. also be carried out on the fibre.

The coupling process may For example the condensation product of butylene-1,2,3,4-dioxides and aromatic amines go onto acetate artificial silk very well from aqueous solution or suspension; they may then be converted into dyestuffs by bringing the material thus treated into solutions of diazo compounds.

Condensation products of buty1ene-1,2,3,4- dioxides with secondary amines may also be em? ployed as coupling components.

As suitable CHICOHN In Germany" December 20."

amines of this kind may be mentioned for example methyl-aniline, ethyl-aniline, normalbutyl-aniline, cyclohexyl-aniline, benzyl-aniline and diphenyl-amine.

On the other hand condensation products of 35 butylene-1,2,3,4-dioxides with aromatic or heterocyclic compounds containing at least one reactive hydrogen atom and which are free from sulphonic j acid groups may be employed as diazo components. 1 Thus for example 1,4-dil-nitro-anilido) -bu m tane-2,3-diol (obtainable by condensation of 1 molecular proportion of butylene-l,2,3,4-dioxide with 2 molecular proportions of para-nitraniline) can be reduced to lA-dipara-phehylenediamidobutane-2,3-diol. This compound is diazotized in 15 the usual manner and the tetrazo compound thus obtained coupled with a coupling component free from sulphonic acid groups, as for example beta-naphthol. V

The following examples will further illustrate 20 how the said invention may be carried out in practice, but the invention is not restricted to these examples. The parts are by weight.

Example 1 25 272 parts of 1,4-dianilidobutane-2,3-diol (obtainable by condensing 2 molecular proportions of aniline with 1 molecular proportion of butylenelj,2,3,4-dioxide) are dissolved in dilute hydro- 30 chloric acid and coupled with a solution of the diazo compound of 138 parts of para-nitraniline.

A yellow brown product is obtained which dyes acetate artificial silk brilliant yellow shades.

A similar dyestufi giving on acetate artificial 35 silk more, golden yellow shades is obtained by employing 1,4-dimeta-toluido butane-2,3-diol instead of 1,4-dianilido-butane-2,3-diol.

Example 2 40 386 parts of 1,4-di-(4-acetamino-anilido) -butane-2,3-dio1 corresponding to the formula 45 /CHrCHOHCHOHCHa\ N N H H V NHGOCH1 alkaline solution of 290 parts of beta-naphthol. V

A dyestufi is formed which dyes acetate artificial silk bluish red shades. 1

What we claim is:

1. Azo dyestufl's corresponding to the g eneral in which the Rs stand for members of the group consisting of 1 hydrogen and alkyl, cycloalkyl,

aralkyl and aryl radicals free from sulfonic acid groups, X and Y stand for radicals of the benzene series free from sulfonic acid groups, Ar stands for an aryl radical free from sulfonic acid groups,

and Z stands fora member of the group consisting of hydrogen and the group -N=NAr.

2. The azo dyestufi of the formula.

V 3. The azo dyestufl of the formula 4.- The azo dyestufi of the formula H H H H HEINRICH HOPFF. 7

- AUGUST W'EICKMANN. 

